1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)nfs_node.c 8.6 (Berkeley) 5/22/95 37 * $FreeBSD: src/sys/nfs/nfs_node.c,v 1.36.2.3 2002/01/05 22:25:04 dillon Exp $ 38 * $DragonFly: src/sys/vfs/nfs/nfs_node.c,v 1.18 2004/12/17 00:18:28 dillon Exp $ 39 */ 40 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/proc.h> 45 #include <sys/mount.h> 46 #include <sys/namei.h> 47 #include <sys/vnode.h> 48 #include <sys/malloc.h> 49 #include <sys/fnv_hash.h> 50 51 #include <vm/vm_zone.h> 52 53 #include "rpcv2.h" 54 #include "nfsproto.h" 55 #include "nfs.h" 56 #include "nfsmount.h" 57 #include "nfsnode.h" 58 59 static vm_zone_t nfsnode_zone; 60 static LIST_HEAD(nfsnodehashhead, nfsnode) *nfsnodehashtbl; 61 static u_long nfsnodehash; 62 63 #define TRUE 1 64 #define FALSE 0 65 66 /* 67 * Initialize hash links for nfsnodes 68 * and build nfsnode free list. 69 */ 70 void 71 nfs_nhinit(void) 72 { 73 nfsnode_zone = zinit("NFSNODE", sizeof(struct nfsnode), 0, 0, 1); 74 nfsnodehashtbl = hashinit(desiredvnodes, M_NFSHASH, &nfsnodehash); 75 } 76 77 /* 78 * Look up a vnode/nfsnode by file handle. 79 * Callers must check for mount points!! 80 * In all cases, a pointer to a 81 * nfsnode structure is returned. 82 */ 83 static int nfs_node_hash_lock; 84 85 int 86 nfs_nget(struct mount *mntp, nfsfh_t *fhp, int fhsize, struct nfsnode **npp) 87 { 88 struct thread *td = curthread; /* XXX */ 89 struct nfsnode *np, *np2; 90 struct nfsnodehashhead *nhpp; 91 struct vnode *vp; 92 struct vnode *nvp; 93 int error; 94 int rsflags; 95 struct nfsmount *nmp; 96 97 /* 98 * Calculate nfs mount point and figure out whether the rslock should 99 * be interruptable or not. 100 */ 101 nmp = VFSTONFS(mntp); 102 if (nmp->nm_flag & NFSMNT_INT) 103 rsflags = PCATCH; 104 else 105 rsflags = 0; 106 107 retry: 108 nhpp = NFSNOHASH(fnv_32_buf(fhp->fh_bytes, fhsize, FNV1_32_INIT)); 109 loop: 110 for (np = nhpp->lh_first; np; np = np->n_hash.le_next) { 111 if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize || 112 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize)) { 113 continue; 114 } 115 vp = NFSTOV(np); 116 if (vget(vp, LK_EXCLUSIVE, td)) 117 goto loop; 118 for (np = nhpp->lh_first; np; np = np->n_hash.le_next) { 119 if (mntp == NFSTOV(np)->v_mount && 120 np->n_fhsize == fhsize && 121 bcmp((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize) == 0 122 ) { 123 break; 124 } 125 } 126 if (np == NULL || NFSTOV(np) != vp) { 127 vput(vp); 128 goto loop; 129 } 130 *npp = np; 131 return(0); 132 } 133 /* 134 * Obtain a lock to prevent a race condition if the getnewvnode() 135 * or MALLOC() below happens to block. 136 */ 137 if (nfs_node_hash_lock) { 138 while (nfs_node_hash_lock) { 139 nfs_node_hash_lock = -1; 140 tsleep(&nfs_node_hash_lock, 0, "nfsngt", 0); 141 } 142 goto loop; 143 } 144 nfs_node_hash_lock = 1; 145 146 /* 147 * Allocate before getnewvnode since doing so afterward 148 * might cause a bogus v_data pointer to get dereferenced 149 * elsewhere if zalloc should block. 150 */ 151 np = zalloc(nfsnode_zone); 152 153 error = getnewvnode(VT_NFS, mntp, &nvp, 0, LK_NOPAUSE); 154 if (error) { 155 if (nfs_node_hash_lock < 0) 156 wakeup(&nfs_node_hash_lock); 157 nfs_node_hash_lock = 0; 158 *npp = 0; 159 zfree(nfsnode_zone, np); 160 return (error); 161 } 162 vp = nvp; 163 bzero((caddr_t)np, sizeof *np); 164 vp->v_data = np; 165 np->n_vnode = vp; 166 /* 167 * Insert the nfsnode in the hash queue for its new file handle 168 */ 169 for (np2 = nhpp->lh_first; np2 != 0; np2 = np2->n_hash.le_next) { 170 if (mntp != NFSTOV(np2)->v_mount || np2->n_fhsize != fhsize || 171 bcmp((caddr_t)fhp, (caddr_t)np2->n_fhp, fhsize)) 172 continue; 173 vx_put(vp); 174 if (nfs_node_hash_lock < 0) 175 wakeup(&nfs_node_hash_lock); 176 nfs_node_hash_lock = 0; 177 zfree(nfsnode_zone, np); 178 goto retry; 179 } 180 LIST_INSERT_HEAD(nhpp, np, n_hash); 181 if (fhsize > NFS_SMALLFH) { 182 MALLOC(np->n_fhp, nfsfh_t *, fhsize, M_NFSBIGFH, M_WAITOK); 183 } else 184 np->n_fhp = &np->n_fh; 185 bcopy((caddr_t)fhp, (caddr_t)np->n_fhp, fhsize); 186 np->n_fhsize = fhsize; 187 lockinit(&np->n_rslock, rsflags, "nfrslk", 0, LK_NOPAUSE); 188 189 /* 190 * nvp is locked & refd so effectively so is np. 191 */ 192 *npp = np; 193 194 if (nfs_node_hash_lock < 0) 195 wakeup(&nfs_node_hash_lock); 196 nfs_node_hash_lock = 0; 197 198 return (0); 199 } 200 201 /* 202 * nfs_inactive(struct vnode *a_vp, struct thread *a_td) 203 * 204 * NOTE: the passed vnode is locked but not referenced. On return the 205 * vnode must be unlocked and not referenced. 206 */ 207 int 208 nfs_inactive(struct vop_inactive_args *ap) 209 { 210 struct nfsnode *np; 211 struct sillyrename *sp; 212 213 np = VTONFS(ap->a_vp); 214 if (prtactive && ap->a_vp->v_usecount != 0) 215 vprint("nfs_inactive: pushing active", ap->a_vp); 216 if (ap->a_vp->v_type != VDIR) { 217 sp = np->n_sillyrename; 218 np->n_sillyrename = NULL; 219 } else { 220 sp = NULL; 221 } 222 if (sp) { 223 /* 224 * We need a reference to keep the vnode from being 225 * recycled by getnewvnode while we do the I/O 226 * associated with discarding the buffers. The vnode 227 * is already locked. 228 */ 229 nfs_vinvalbuf(ap->a_vp, 0, ap->a_td, 1); 230 231 /* 232 * Either we have the only ref or we were vgone()'d via 233 * revoke and might have more. 234 */ 235 KKASSERT(ap->a_vp->v_usecount == 1 || 236 (ap->a_vp->v_flag & VRECLAIMED)); 237 238 /* 239 * Remove the silly file that was rename'd earlier 240 */ 241 nfs_removeit(sp); 242 crfree(sp->s_cred); 243 vrele(sp->s_dvp); 244 FREE((caddr_t)sp, M_NFSREQ); 245 } 246 np->n_flag &= (NMODIFIED | NFLUSHINPROG | NFLUSHWANT | NQNFSEVICTED | 247 NQNFSNONCACHE | NQNFSWRITE); 248 return (0); 249 } 250 251 /* 252 * Reclaim an nfsnode so that it can be used for other purposes. 253 * 254 * nfs_reclaim(struct vnode *a_vp) 255 */ 256 int 257 nfs_reclaim(struct vop_reclaim_args *ap) 258 { 259 struct vnode *vp = ap->a_vp; 260 struct nfsnode *np = VTONFS(vp); 261 struct nfsmount *nmp = VFSTONFS(vp->v_mount); 262 struct nfsdmap *dp, *dp2; 263 264 if (prtactive && vp->v_usecount != 0) 265 vprint("nfs_reclaim: pushing active", vp); 266 267 if (np->n_hash.le_prev != NULL) 268 LIST_REMOVE(np, n_hash); 269 270 /* 271 * For nqnfs, take it off the timer queue as required. 272 */ 273 if ((nmp->nm_flag & NFSMNT_NQNFS) && np->n_timer.cqe_next != 0) { 274 CIRCLEQ_REMOVE(&nmp->nm_timerhead, np, n_timer); 275 } 276 277 /* 278 * Free up any directory cookie structures and 279 * large file handle structures that might be associated with 280 * this nfs node. 281 */ 282 if (vp->v_type == VDIR) { 283 dp = np->n_cookies.lh_first; 284 while (dp) { 285 dp2 = dp; 286 dp = dp->ndm_list.le_next; 287 FREE((caddr_t)dp2, M_NFSDIROFF); 288 } 289 } 290 if (np->n_fhsize > NFS_SMALLFH) { 291 FREE((caddr_t)np->n_fhp, M_NFSBIGFH); 292 } 293 if (np->n_rucred) { 294 crfree(np->n_rucred); 295 np->n_rucred = NULL; 296 } 297 if (np->n_wucred) { 298 crfree(np->n_wucred); 299 np->n_wucred = NULL; 300 } 301 302 vp->v_data = NULL; 303 zfree(nfsnode_zone, np); 304 return (0); 305 } 306 307 #if 0 308 /* 309 * Lock an nfsnode 310 * 311 * nfs_lock(struct vnode *a_vp) 312 */ 313 int 314 nfs_lock(struct vop_lock_args *ap) 315 { 316 struct vnode *vp = ap->a_vp; 317 318 /* 319 * Ugh, another place where interruptible mounts will get hung. 320 * If you make this sleep interruptible, then you have to fix all 321 * the VOP_LOCK() calls to expect interruptibility. 322 */ 323 while (vp->v_flag & VXLOCK) { 324 vp->v_flag |= VXWANT; 325 (void) tsleep((caddr_t)vp, 0, "nfslck", 0); 326 } 327 if (vp->v_tag == VT_NON) 328 return (ENOENT); 329 330 #if 0 331 /* 332 * Only lock regular files. If a server crashed while we were 333 * holding a directory lock, we could easily end up sleeping 334 * until the server rebooted while holding a lock on the root. 335 * Locks are only needed for protecting critical sections in 336 * VMIO at the moment. 337 * New vnodes will have type VNON but they should be locked 338 * since they may become VREG. This is checked in loadattrcache 339 * and unwanted locks are released there. 340 */ 341 if (vp->v_type == VREG || vp->v_type == VNON) { 342 while (np->n_flag & NLOCKED) { 343 np->n_flag |= NWANTED; 344 (void) tsleep((caddr_t) np, 0, "nfslck2", 0); 345 /* 346 * If the vnode has transmuted into a VDIR while we 347 * were asleep, then skip the lock. 348 */ 349 if (vp->v_type != VREG && vp->v_type != VNON) 350 return (0); 351 } 352 np->n_flag |= NLOCKED; 353 } 354 #endif 355 356 return (0); 357 } 358 359 /* 360 * Unlock an nfsnode 361 * 362 * nfs_unlock(struct vnode *a_vp) 363 */ 364 int 365 nfs_unlock(struct vop_unlock_args *ap) 366 { 367 #if 0 368 struct vnode* vp = ap->a_vp; 369 struct nfsnode* np = VTONFS(vp); 370 371 if (vp->v_type == VREG || vp->v_type == VNON) { 372 if (!(np->n_flag & NLOCKED)) 373 panic("nfs_unlock: nfsnode not locked"); 374 np->n_flag &= ~NLOCKED; 375 if (np->n_flag & NWANTED) { 376 np->n_flag &= ~NWANTED; 377 wakeup((caddr_t) np); 378 } 379 } 380 #endif 381 382 return (0); 383 } 384 385 /* 386 * Check for a locked nfsnode 387 * 388 * nfs_islocked(struct vnode *a_vp, struct thread *a_td) 389 */ 390 int 391 nfs_islocked(struct vop_islocked_args *ap) 392 { 393 return VTONFS(ap->a_vp)->n_flag & NLOCKED ? 1 : 0; 394 } 395 #endif 396 397